Validate and Protect Data

Transcription

1 Validate and Protect Data Chapter 8 Objectives In this section you will Restrict Data Entry to a Cell Test the Data Entered in a Cell for Validity Display Instructions for Data Entry Display Error Messages Create Lists of Data Entries to Choose from Allow Conditional Formatting Protect Files against Modification Set Passwords We will look at validations using the example of the advertising budget. Open the file Validation Q1 Q2 Q3 Q4 TOTAL Units Sold Sales Revenue Cost of Sales Advertising Overhead Profit This model is set up so that all values are driven by advertising There are two constraints on this model Total Advertising cannot exceed $40,000 for the year No more than $12,000 can be spent on advertising in any quarter We will use Validation techniques to ensure users of this sheet only use valid choices when considering the data entries they make in the advertising budget. Validate and Protect Data

2 Complex Microsoft Excel 2003 for Business Specify Valid Data Entries A simple validation to restrict entry into a cell, is to set the limit for $12,000 on advertising in any quarter. Click on C7 the Advertising cell for the 1 st quarter Click on Data Validation in the Menu bar Click on the Settings tab if necessary The Data Validation window will appear with the Allow box with the default setting of Any value. Click on the Allow box and select Whole number Allow Type 0 in the Minimum box Type in the Maximum box Repeat this process for each of the advertising cells, D7, E7 and F7 NOTE: The settings for several cells can be set at once by highlighting all cells then applying the setting to all. You are doing it one at a time just for practice. 8-2 Microstar Publishing Pty Ltd 2003

3 Validate and Protect Data 8 Testing the Validation settings Validation settings you make should always be tested with both acceptable data and unacceptable data. The response of the Validation should be monitored to check it is working as required. For validation where the data should be between, and including, 0 and 12,000, the testing data could be any number between 0 and 12,000 to check response when accurate data is entered 12,000 and 0 as these are the maximum and minimum boundaries of valid data numbers less than 0 eg 1,000, -2,500 numbers greater than 12,000, 13,000, 12,001 etc. Now we will test the validation by making a data entry into the cell. Click on Cell C7, type 13,000 and press [Enter] A message should appear. At this point the user will realise a mistake has been made, but no useful information has been given yet as to how to fix the problem. Click on Retry Type 12,000 and press [Enter] The data will be accepted. Microstar Publishing Pty Ltd

4 Complex Microsoft Excel 2003 for Business Display a Message when a Cell is Selected A message can be displayed as soon as a user clicks on a cell. Select C7 Click on Data Validation in the Menu bar Click on the Input Message tab Enter a Title and Input message as shown below Click on Show input message until a tick appears to ensure the message is displayed when the cell is selected Input Message tab Check that this is ticked so message will appear when cell is selected Title Input Message Repeat this process for each of the advertising cells, D7, E7 and F7 Now whenever one of the advertising cells is selected the message will appear. 8-4 Microstar Publishing Pty Ltd 2003

5 Validate and Protect Data 8 Display a Message when Invalid Data is Entered Click on cell C7 Click on Data Validation in the Menu bar Click on the Error Alert tab Enter the Title and Error message as shown below Error Alert Title This data is outside the allowable range. The amount cannot be more than $12000 Error Message Try typing in C7 and press [Enter] The following message should appear. Click on Retry and enter into cell C7 The data should be accepted. Repeat these steps to set the error messages for the other advertising cells Microstar Publishing Pty Ltd

6 Complex Microsoft Excel 2003 for Business Other styles of messages are available to use with invalid data entry. Click on C7 again and Data Validation in the Menu bar Click on the Error Alert tab if necessary Click on the Style box to display the other styles of messages Warning and Information Style of Messages The Warning Message The warning message uses the text "Continue?", followed by Yes, No, and Cancel buttons, with No as the default button Click Warning in the Style box Type in cell C7 and press [Enter] The following warning message will appear. The consequences of using each button are explained on the following page. 8-6 Microstar Publishing Pty Ltd 2003

7 Validate and Protect Data 8 Using the Yes button of a Warning message overrides the validation rule and enters the invalid data. Using the No button of a Warning message returns to the cell for the correct data to be entered. Using the Cancel button of a Warning message returns the original value in the cell. Try entering invalid data into the cell C7 using each of the buttons Use an Information Message Click on Data Validation in the Menu bar Click on the Error Alert tab if necessary Click on the Style box and select Information Type in cell C7 The OK button allows the entry of the invalid data in the cell. The Cancel button restores the previous value to the cell. If you don't enter any text in the Error message box, the message displays the following: Note: Any message is displayed only when a user types data in the cell. Formulas that calculate invalid data, or data placed in the cell by a macro, do not cause the error message to be displayed. Microstar Publishing Pty Ltd

8 Complex Microsoft Excel 2003 for Business Identify Invalid Values in Cells Invalid entries in cells can be identified using the Circle Invalid Data tool on the Auditing toolbar. This tool will locate data that was invalid when typed in directly and ignored as a problem by the user, or cells that are, by result of a calculation, invalid. You may want to use this tool to check your own work or that of another user. Click on Tools Formula Auditing Show Formula Auditing toolbar in the Menu bar On the Auditing toolbar, click Circle Invalid Data Circle Invalid Data Any values displayed in the worksheet that are invalid will be circled. If no circles appear on the sheet reenter some invalid data into the advertising cells. Clear Invalid Data Circles Click on Clear Validation Circles Circle Invalid Data 8-8 Microstar Publishing Pty Ltd 2003

9 Validate and Protect Data 8 Finding Cells that have Invalid Data as a Result of Calculations The Profit cells have values that are a result of formula calculations. A restriction can be placed on the result of the calculations with an appropriate error message. However the error message will not appear when the result is calculated. The invalid nature of the result will only be indicated by the red invalid data circles. Suppose the resulting profits for each quarter must be at least 40,000. Highlight cells C10:F10 Click on Data Validation in the Menu bar Enter the following in the Settings tab notice that Allow has Decimal Enter the following data in the Advertising cells Click on the Circle Invalid Data button to display all invalid cells Click on the Clear Validations Circles button Microstar Publishing Pty Ltd

10 Complex Microsoft Excel 2003 for Business Restrict Data Entry to Values on a List Suppose it is decided that the amounts entered for the advertising for each quarter must be rounded to the nearest thousand and between 8000 and These amounts can be put in to a list from which a selection is made. On the same worksheet, type the list of valid entries down a single column or across a single row. Do not include blank cells in the list Select C7 as the cell that you want to restrict Click on Data Validation in the Menu bar Click on the Settings tab Click in the Allow box and click on List Source Click in the Source box and highlight the cells for the list B14 to F14 Now make some entries into the cell using the list button Click on the list button for the cell and click on one of the values List button Repeat the whole process for the other advertising cells 8-10 Microstar Publishing Pty Ltd 2003

11 Validate and Protect Data 8 Determine valid entries for a cell by using a formula Formula can be used to decide if an entry is valid. The formula should calculate a logical value, i.e. True or False. The formula should start with an equal sign (=) In this example we must check that the total of the advertising budgets for the quarters does not exceed $40,000 Highlight the cells C7:F7 to select the cells for Advertising (just the Qtrs, not the Total) Click on Data Validation in the Menu bar Click on the Settings tab Click on the Allow box and click on Custom Click on the Formula box and clear anything there Allow Enter the formula =40000>=sum($C$7:$F$7) This calculation will add the entries in the advertising cells each time an entry is made into one of them. If the calculation returns a TRUE answer, i.e. the sum of advertising amounts is less than $40,000, life goes on! However if a false result is returned then the error message is displayed. and try making some entries into the cells Microstar Publishing Pty Ltd

12 Complex Microsoft Excel 2003 for Business Finding Cells that have Data Restrictions or Messages The cells that have validation settings can be quickly identified in the spreadsheet. Click on Edit Go To in the Menu bar Click on the Special button Special The Go To Special window appears as shown below. Click on Data validation To find every cell on the worksheet that has data restrictions or messages, click All The cells with Data Validation applied will be highlighted. NOTE : If you want to find only those cells with the same data restrictions and messages as a particular cell, then start these steps by clicking on that cell and click Same in the Go To Special dialog box Microstar Publishing Pty Ltd 2003

13 Validate and Protect Data 8 Remove Data Restrictions and Messages To practice removing restrictions we will remove them from the 2 nd, 3 rd and 4 th Qtr Advertising amounts. In the next section we will copy them back. These steps will remove the restrictions but leave any data or formula in the cell. Click on cell D7 Click on Data Validation in the Menu bar then click the Settings tab. Click Clear All to clear all entries on the Settings, Messages and Error Alert tabs Clear All Repeat the steps above to clear the data restrictions for Advertising in Qtrs 3 and 4, i.e. cells E7 and F7 NOTE 1: All cells could be cleared at once by highlighting them then using the same steps. NOTE 2: To clear the cell of all data or formulae and the data restrictions just use Edit Clear All in the Menu bar Microstar Publishing Pty Ltd

14 Complex Microsoft Excel 2003 for Business Copy Data Restrictions and Messages to other Cells Click C7 as it should still have the Validation settings Click on the Copy button in the toolbar Highlight D7 Click on Edit Paste Special in the Menu bar Click on Validation and then OK Validation Repeat for E7 then F7 NOTE: You could copy to all the cells at once by highlighting them together, it was done one at a time here purely for practice Close the Validation file 8-14 Microstar Publishing Pty Ltd 2003

15 Validate and Protect Data Protecting Workbooks and Cells Once you have created a workbook you can protect all of your hard work by protecting the workbook, or parts of it, by restricting access and the ability to make changes to the workbook. Microsoft Excel provides several ways to allow you to limit the ability of unauthorised people to see and change a workbook after it is opened. Preventing Workbook Files from being Opened or Saved You can assign protection to a whole workbook in order to prevent unauthorised people from opening it, accessing it, or saving changes to it. Microsoft Excel provides three levels of workbook protection: Password protection prevents people who don't know the password, from opening the workbook. Write-reservation protection enables people to open the workbook, but they can't save changes to it without knowing the password. Read-only recommended protection enables people to choose whether to open the workbook as a read-only file or to open it as a read-write file. You can assign any of these levels of protection by using the Save As command on the File menu. Caution! If you assign password protection to a workbook and then forget the protection password, you can't open the workbook, remove protection from the workbook, or recover data from the workbook. It's a good idea to keep a list of your passwords and their corresponding workbook and sheet names in a safe place. (Passwords are case sensitive i.e. Goose is not the same as goose.) Microstar Publishing Pty Ltd

16 Complex Microsoft Excel 2003 for Business Making a File Readonly A file can be made Read Only. This is where a user can open a file and look at its contents however if changes are made to the spreadsheet the file must be saved with a different name so that the original file is unchanged. Open the file Readonly Click on File Save As in the Menu bar Click on Tools at the top of the Save As dialog box Click on General Options Tools Check the Read-only recommended box Type protects in the Password to modify box The prompt to confirm the password you entered will appear. Type the password protects again in the box and click on OK Click on Save to save the file, then Yes to Replace Existing File Close the file 8-16 Microstar Publishing Pty Ltd 2003

17 Validate and Protect Data Opening a Modify Restricted File with a Password Open the file Readonly The password prompt will appear Type the password protects and click on OK (NOTE : If a user didn t know the password they could still click on the Read Only button to just look at the file ) A Read Only prompt will appear - this is because the Read-Only recommended box was checked. Click on No to be able to make changes to the file you have the authority to make changes because you used the password to open the file Close the file Opening a Modify Restricted File without a Password Open the file ReadOnly Click on the Read Only button Try making some changes to the file, then click on the Save button The following prompt will appear. to save the changes to this file you would have to use another name Microstar Publishing Pty Ltd

18 Complex Microsoft Excel 2003 for Business Allowing Access to a File with a Password We will create a file called COMMPASS protected with password COMM. Open the file COMM Click on File Save As so we can give the file a new name and apply the password Name the file COMMPASS Click on Tools General Options Type the password COMM in the Save Options box in the Password to open - asterisks will appear instead of the word A prompt will appear to repeat the password again to set it Type the password again then click on OK Save and Close the file Only users who know the password can have access to this file. Open the file COMMPASS The Password prompt will appear. Type the password COMM into the password box and click OK The file should open. If it doesn t you may have used the wrong case when entering the password, a common mistake. Just try opening the file again and be careful entering the password. Close the file 8-18 Microstar Publishing Pty Ltd 2003

19 Validate and Protect Data Protecting Worksheets It is possible to protect individual cells in a worksheet or book so that formula and other items cannot be changed, however there will be cells that will need to be unprotected so that data can be entered. For example in this sheet, the Totals values and headings need to be protected as the values are the result of formula. The data area in each of the three columns must stay unprotected so that entries can be made. There are two steps to protecting a sheet: Locking cells Protecting the sheet We will look at how to lock cells first. Then we will look at how to protect the sheet, once cells are locked. Microstar Publishing Pty Ltd

20 Complex Microsoft Excel 2003 for Business Locking Workbook Cells It is a default setting that all cells are locked. However the cells do not become protected until protection is switched on. So even though the cells are set to be locked they can still be changed until the protection is switched on. Open the Tour spreadsheet Select the cells you want to protect E3:E15 (NOTE: you can select several ranges at once using the [Ctrl] key, select the first range then hold down the [Ctrl] key while you select the other ranges as shown in the picture below) Using the [Ctrl] key, select the months and the headings Click on Format Cells in the Menu bar Click on the Protection tab Protection Locked cells can't be edited when the document is protected. Hidden cells display their values, but the formula is not displayed in the formula bar. Click on Locked so a tick appears (if necessary) Note: Locking cells has no effect unless the sheet is protected. Before protecting the sheet, ensure any cells you want to be able to be changed by users, are not locked Microstar Publishing Pty Ltd 2003

21 Validate and Protect Data Unlocking Workbooks Cells There will be cells that you don t want protected because data must be entered. These steps will allow changes to be made to these cells even when the sheet is protected. Highlight the range of cells B3:D14 Click on Format Cells Protection tab Uncheck the Locked and Hidden boxes so that they are clear Protect a Sheet Once you have set which cells are to be locked and which cells are to be changeable you must protect the sheet so that these settings can be enforced. Click on Tools Protection in the Menu bar Click on Protect Sheet The Protect Sheet box will appear. At this point we can set exactly what is to be protected, or place a password to prevent unauthorised users from removing the protection. Now try to make changes to various cells. You should be able to change the sales figures in the data area, however an attempt to change a Total cell will bring up an error prompt. Microstar Publishing Pty Ltd

22 Complex Microsoft Excel 2003 for Business To Remove Sheet Protection Click Tools Protection in the Menu bar Click on Unprotect Sheet It will appear as though nothing has happened however if you try to make changes to the Totals cells you will be able to. Close the file Practice Exercise 8.1 Open the file GoalSeek You are going to protect the worksheet except for the cells where the amount of pay per week is entered. Highlight the cells B6:B15 Click on Format Cells in the Menu bar Click on the Protection tab and click on the Locked box to clear the tick to close the Format Cells dialog box Click on Tools Protection Protect Sheet and OK Save the file as Protected Goal Seek then Close 8-22 Microstar Publishing Pty Ltd 2003

23 Validate and Protect Data Practice Exercise Open the file Ch8 Protection and display the Advert worksheet This worksheet contains many formulas. It is designed so that the only cells in which the user should enter data are C7:F7. To protect the setup of the worksheet you are to protect all of the cells except those. 2. Highlight all of the cells and check that they are locked, then highlight just the cells C7:F7 and unlock them 3. Protect the sheet Practice Exercise Click on the Renovations worksheet of the Ch8 Protection file. 2. This sheet is designed so that data can be entered in cells C4 and C6 to C9. Lock the other cells and protect the worksheet. Microstar Publishing Pty Ltd

24 Complex Microsoft Excel 2003 for Business Practice Exercise Display the worksheet Wedding of the Ch8 Protection file. 2. Look at the spreadsheet and determine which cells should be protected and which should remain unlocked. Cells containing formula should definitely be locked. 3. Protect the sheet 4. To check your work, enter the following quote details by another caterer. You should be able to enter data as shown below. 5. You should not be able to make entries in cells C6, C7, C11 and C Make any changes necessary then save and close the file 8-24 Microstar Publishing Pty Ltd 2003